Novel chemical intermediates used in producing 4- and 5-phenyl-pentenals

ABSTRACT

Novel Schiff base intermediates used in producing 4- or 5phenyl-pentenals, having the structure:   WHEREIN X is a moiety selected from the group consisting of:   AND WHEREIN Ra is hydrogen or methyl; wherein n is 0 when Ra is methyl and n is 1 when Ra is hydrogen.

United States Patent [191 Schreiber et al.

[ Aug. 5, 1975 [73] Assignee: International Flavors & Fragrances Inc.,New York, N.Y.

22 Filed: Sept. 19, 1974 21 Appl.No.:507,4l5

Related U.S. Application Data [62] Division of Ser. No. 283,632, Aug.25, 1972, Pat. No.

[52] U.S. Cl 260/566 R {51] C07C 119/00 [58] Field of Search 260/566 R[56] References Cited UNITED STATES PATENTS 3,716,498 2/1973 Halli252/522 Primary Examiner-Gerald A. Schwartz Attorney, Agent, orFirm-Arthur L. Liberman, Esq.; Harold Haidt, Esq.

[57] ABSTRACT Novel Schiff base intermediates used in producing 4- orS-phenyl-pentenals, having the structure:

wherein X is a moiety selected from the group consisting of:

, R OH and wherein R is hydrogen or methyl; wherein n is 0 when R,, ismethyl and n is 1 when R is hydrogen.

3 Claims, No Drawings NOVEL CHEMICAL INTERMEDIATES USED IN PRODUCING 4-AND S-PHENYL-PENTENALS This application is a division of applicantscopending parent application Ser. No. 283,632 filed on Aug. 25, 1972 nowU.S. Pat. No. 3,862,340.

BACKGROUND OF THE INVENTION The present invention relates to novelmethods and compositions using certain 4- or 5-phenyl-pentenals,

and lower alkyl or lower alkylene acetals, a number of which are novelthemselves, to alter the flavor and/or aroma of consumable materials.The above-mentioned acetals may also act as precursors for theircorresponding free aldehydes which alter the flavor and/or aroma ofconsumable materials.

There has been considerable work performed relating to substances whichcan be used to impart flavors and fragrances to various consumablematerials. These substances are used to diminish the use requirement ofnatural materials some of which may be in short supply and to providemore uniform properties in the finished product. Citrus flavors, walnutflavors, chocolate flavors, cinnamon flavors, green vegetable flavors,watermelon flavors, cucumber flavors, green floral aromas, green twiggyaromas, and cinnamon aromas are particularly desirable for many uses inconsumable materials.

3-Phenyl-pentenals have been suggested in U.S. Pat. application Ser. No.43,555, filed June 4, 1970 now U.S. Pat. No. 3,694,232 for use in cocoaflavors whereby notes characteristic of milk chocolate are provided.

3-Phenyl-4-pentenal is indicated to cause the chocolate beverage to havea fuller, richer sweet milk chocolate flavor. U.S. Pat. No. 3,582,360issued on June 1, 1971 discloses certain 2-phenyl-2-alkenals as beinguseful for preparing flavoring compositions and food compositions,particularly those having chocolate or cocoa flavors and/or aromaqualities. Thus, for example, the compound S-methyl-2-phenyl-2-hexenalis indicated therein to alter imitation cocoa flavor so as to provide amore natural cocoa flavor and impart a character of bitter chocolate.

Acetals are shown to be useful in fragrance formulation at Column 2,lines 50-65 of U.S. Pat. No. 3,636,1 13. Such acetals have thestructures:

wherein R, and R are either hydrogen or lower alkyl; wherein R and R arethe same or different lower alkyl groups, and

wherein n is l or 2 and lower alkylene cyclic acetals having thestructure wherein R is lower alkylene.

In U.S. application Ser. No. 43,555 mentioned above, mention is made ofthe diethyl acetal of 3-phe-- nyl-4-pentenal and the diethyl acetal of3-phenyl-3- pentenal; but only as intermediates for producing3-phenyl-3-pentenal and 3-phenyl-2-pentenal from 3-phenyl-4-pentenal.

In West et al. Synthetic Perfumes: their Chemistry and Preparation,published by Edward, Arnold & Co., London, England, in 1949, on page 315cinnamaldehyde dimethyl acetal is stated to have a fine cinnamon-cassiaodor which renders it useful in some Cha nellike fancy perfume and inoriental types like Tabac Blond and Fleur de Tabac". Cinnamaldehydcdiethyl acetal is also reported. These materials have the followingstructures:

wherein R is methyl or ethyl.

Cinnamaldehyde diethyl acetal is reported in Perfume and FlavorChemicals (Aroma Chemicals) by S. Arctander (published by the author inMontclair, NJ. 1 1969) as having a faint but fresh green slightly spicyoily sweet odor and a mild and oily sweet taste." Arctander goes on tostate: since this acetal like most other acetals is unstable undermildly acid conditions it finds little if any use in flavorcompositions. In addition, Arctander also reports cinnamaldehyde 2,4-dihydroxy-4-methyl-pentane acetal as soft, tenacious, natural, cinnamontype odor not nearly as harsh as cinnamic aldehyde yet rich and lastingas aldehyde itself. Cinnamic aldehyde dimethyl acetal is also reportedby Arctander and with reference to this acetal Arctander states: Itshould be noted that pure, aldehdye-free acetal is practically colorlessand carries little or no odor similarily to the aldehyde. The ethyleneglycol acetal of cinnamic aldehyde is indicated by Arctander to beuseful in flavor compositions, such as all spice, cassia, cinnamon,clove and various spice blend and it is stated by Arctander to have asweet spicy cinnamon all spice taste not quite as sweet as the aldehyde.It should be noted that cinnamic aldehyde ethylene glycol acetal is onthe GRAS list and has been given F.E.M.A. No.2287.

The cinnamic aldehyde acetals of the prior art are not considered toimpart certain desired qualities to consumable materials which acetalsof 4- and S-phenylpentcnals of this invention are capable of doing asmore specifically described below.

The prior art cinnamic aldehyde acetal noted above,

however, being unsaturated in a position :,[3- to the acetal moiety, arerelatively unstable even in aqueous media.

It has now been discovered that novel solid and liquid foodstuff andflavoring compositions as well as novel aroma imparting compositionshaving citrusy, and/or walnut, and/or chocolate, and/or cinnamon, and/orgreen vegetable, and/or watermelon, and/or cucumber, and/or greenfloral, and/or green twiggy characteristics found in quality essencesand essential oils may be provided by the utilization of certaincompounds of the class of 4- and S-phenyl-pentenals and lower alkyl andlower alkylene acetals thereof.

Furthermore, certain lower alkyl and lower alkylene acetals of the 4-and S-phenyl-pentenals of this invention will act as precursors informing the corresponding freealdehydes of this invention. Theseprecursors are uniquely useful in that they may be included, preferably,as part of a solid flavor or fragrance imparting composition which iscapable of being stored for an indefinite period of time prior to use ina liquid foodstuff or in a perfume formulation or in a cologne. At thepoint of ultimate use of the flavor or fragrance imparting material,such higher molecular weight acetal is hydrolyzed due to the presence ofother acidic constituents and/or an aqueous medium and due to the liquidphase of the material in which it is used.

The term 4- or S-phenyl-pentenal and lower alkyl and alkylene acetalsthereof as used herein is intended to encompass compounds having thestructure:

wherein one of X or Y is phenyl and the other of X and Y is hydrogen;wherein one of the wavy or dashed lines is a carbon-carbon double bondand the other two of the wavy or dashed lines is a carbon-carbon singlebond; wherein the dashed line is a single bond when X is hydrogen; andwherein A is a moiety selected from the group consisting of and whereinR,, and R,, separately arc the same or different lower alkyl or R,, andR taken together form a lower allcylene group,

Specific examples of compounds falling within the scope of the foregoingstructural formula include, without limitation, the following:

5-phcnyl-4-pentcnal S-phcnyl-Z-pentcnal 4-phenyl-4-pentenal4-phenyl-3-pentenal I 4-phenyl-4-pentena die-thy] acetal"4-phenyl-3-pentenal diethyl acetal 4-phenyl-2-penten al diethyl acetal5-phenyl-4-pentenal dimethyl' acetal 5-phenyl-2-pentenal dimethyl.acetal 4-phenyl-4-pentenal dimethyl acetal 4-phenyl-3-pentenal dirnethylacetal 4-phenyl-2-pentenal dimethyl acetal 5-phenyl-4-pentenal ethyleneacetal S-phenyI-Z-pentenal ethylene acetal 4-phenyl-4-pentenal ethyleneacetal 4-phenyl-3-pentenal ethylene acetal 4-phenyl-2-pentenal ethyleneacetal 5-phenyl-4-pentenal l,2-propylene acetal S-phenyl-Z-pentenal1,2-propylene acetal 4-phenyl-4-pentenal l,2-propylene acetal4-phenyl-3-pentenal 1,2-propylene acetal 4-phenyl-2-pentenall,2-propylene acetal 5-phenyl-4-pentenal methyl ethyl acetal5-phenyl-2-pentenal methyl ethyl acetal 4-phenyl-4-pentenal methyl ethylacetal 4-phenyl-3-pentenal methyl ethyl acetal 4-phenyl-2-pentenalmethyl ethyl acetal 5-phenyl-4-pentenal di-n-propyl acetal5-phenyl-2-pentenal di-n-propyl acetal 4-phenyl-4-pentenal di-n-propylacetal 4-phenyl-3-pentenal di-n-propyl, acetal 4-phenyl-2-pentenaldi-n-propyl acetal 5-phenyl-4-pentenal di-i-propyl acetal5-phenyl-2-pentenal di-i-propyl acetal 4-phenyl-4-pentenal di-i-propylacetal 4-phenyl-3-pentenal di-i-propyl acetal 4-phenyl-2-pentenaldi-i-propyl acetal 5-phenyl-4-pentenal di-n-butyl acetal5-phenyl-2-pentenal di-n-butyl acetal 4-phenyl-4-pentenal di-n-butylacetal 4-phenyl-3-pentenal di-n-butyl acetal 4-phenyl-2-pentenaldi-n-butyl acetal 5-phenyl-4-pentenal 1,3-n-butylene acetal5-phenyl-2-pentenal l,3-n-butylene acetal 4-phenyl-4-pentenall,3-n-butylene acetal 4-phenyl-3-pentenal 1,3-n-butylene acetal4-phenyl-2-pentenal 1,3-n-butylene acetal The instant inventionfurthermore is intended to encompass certain novel compounds included inthe above-mentioned list. These novel compounds are broadly defined bythe structure:

Y Q WA wherein one of X and Y is pheriyl and the other of X and Y ishydrogen and A is a moiety selected from the group consisting of C & O H

and Ri wherein R,, and R',, separately are the same or different loweralkyl or R and R',, taken together form a lower alkylene group.

Specific examples of these novel compounds are:

5-phenyl-4-pentenal 5 4-phenyl-4-pentenal 5-phenyl-4-pentenal dimethylacetal 4-phenyl-4-pentenal dimethyl acetal 5-phenyl-4-pentenal diethylacetal 4-phenyl-4-pentenal diethyl acetal 5-phenyl-4-pentenal ethyleneacetal 4-phenyl-4-pentenal ethylene acetal 5-phenyl-4-pentenal1,2-n-propylene acetal 4-phenyl-4-pentenal 1,2-n-propylene acetal5-phenyl-4-pentenal 1,3-n-butylene acetal 4-phenyl-4-pentenall,3-n-butylene acetal 5-phenyl-4-pentenal di-n-butyl acetal4-phenyl-4-pentenal di-n-butyl acetal 5-phenyl-4-pentenal di( Z-methyll-propyl)acetal 4-phenyl-4-pentenal di(Z-methyll -propyl )acetal Examplesof food flavor and fragrance properties of the 4- and S-phenyI-pentenalswhich are preferred in the practice of the instant invention are asfollows:

1. 4-Phenyl-4-pentenal:

Aroma: Green, balsamic fatty; faint woody, nutty, twiggy, citrus cortex;includes a slight green spicelike aromatic nuance.

Taste: at 0.5 ppm has a fresh walnut kernel pumpkinseed-like taste. At 2ppm has an additional watermelon cucumber character. At 10 ppm has agreen primary flavor and a metallic, cedar, watermelon rind secondaryflavor. Threshold level: 0.1 ppm.

2. 4-Phenyl-2-pentenal:

Aroma: Has a green, twiggy, cuminic, cortex-like, cinnamon, carvone-likearoma.

Taste: at l and 2 ppm it has a sweet chocolate-like rosy aroma. At 1 ppmhas sweet and melon notes. At 2 ppm has a milk chocolate character. At10 ppm primary flavor is floral and woody and has a secondary cedarflavor. Threshold level: 1 ppm.

Ta's't'e At 2 ppm has a fruity, characteristics fresh grapefruit note.At 10 ppm has a green primary flavor and a floral, watermelon, rindsecondary flavor. Threshold Level: 1 ppm.

Aroma: Has a green slight cinnamon note with a natural fattiness.

4 5-Phe'n'yl-2-pentcnal:

Aroma: Has a green, cutgrass, linseed, cinnamon, sweet aromatic, citrus,lemon and lime-like aroma. At 1 :ppm has a light rosy aroma.

T-a's't'e: At 2 ppm has a sweet, cinnamon bark line taste with agrapefruit note. At 10 ppm has a green primary flavor with a floral,watermelon, rind secondary flavor. Threshold level: 1 ppm.

As used herein in regard to flavors the term alter in its various formsmeans supplying or imparting a flavor character or note to an otherwisebland, relatively tasteless substance, or augmenting the existing flavorcharacteristic where a natural flavor is deficient in some regard, orsupplementing the existing flavor impression to modify its quality,character or taste.

As used herein the term foodstuff includes both 65 solid and liquidingestible materials which usually do, but need not, have nutritionalvalue. Thus, foodstuffs include meats, gravies, soups, conveniencefoods, beverages, dairy products, candies, vegetables, cereals,

soft drinks, snacks and the like.

The preparation of 5-phenyl-4-pentenal and 4-phenyl-4-pentenal is mostpreferably carried out by means of reaction of a phenyl allyl bromide(e.g. cinnamyl bromide,

: A ,Br

where it is desired to produce 5-phenyl-4-pentenal and oz-bromomethylstyrene. 1

where it is desired to produce 4-phenyl-4-pentenal) with the lithiumsalt of a Schiff base of acetaldehyde with a primary amine (e.g. aSchiff base of acetaldehyde with cyclohexylamine, or t-butylamine orisopropylamine) thereby forming a 4- or 5-phenyl-4- pentenal Schiffbase. This Schiff base is then hydrolyzed thus forming the desired freealdehyde. The free aldehyde may, if desired, then be reacted with asuitable orthoformate and, in addition, a lower alcohol or mixture ofdifferent lower alcohols or a lower alkylene glycol or a mixture oflower alkylene glycols or a mixture of lower alcohols and lower alkyleneglycols in the presence of an acidic reaction promoter such asparatoluene sulfonic acid, hydrochloric acid or a source therefor suchas acetyl chloride, thus forming one or a mixture of lower alkyl acetalsand/or lower alkylene glycol acetals which are also useful in ourinvention. The reaction sesquence is generally illustrated as follows:

/ (CH Br n r @lgjT ko n Acid Catalyst wherein n is zero when m is l andn is 1 when m is zero; together form a lower alkylene group, e.g. 1,2-

and wherein R,, and R',, taken separately are the same th lenl,3-propylene; 1,3-butylene; l,4-butylene; different lower y gy y n-p pyand l,2-propylene. A specific illustration of this reacpropyl, n-butyl,t-butyl or i-butyl and R,, and R',, taken tion sequence is as follows:

cone. @W

The preparation of the reactant, the lithium salt of the Schiff base ofacetaldehydeis carried out by first forming a Schiff base of an amine,such as cyclohexylamine or isopropyl amine with acetaldehyde. An organolithium compound in a suitable solvent (e.g. nbutyl lithium or phenyllithium in hexane, diethyl ether benzene or mixtures thereof) is thenintimately admixed with an amine such as diisopropyl amine or di(-trimethylsilyl) amine to form a lithium amide salt. To the resultingsolution at 0C, the Schiff base is added thereby forming the lithiumsalt of the Schiff base. The reaction between the lithium salt of theSchiff base thus formed and the phenyl allyl bromide is best carried outin equimolar proportions at temperatures in the range of 70C up to +30C,the most preferable technique being to allow the reaction mass to warmup from 70C up to +20C. The subsequent acidification is preferablycarried out at a pH of approximately 1 using, preferably hydrochloricacid or sulfuric acid.

The preparation of 5-phenyl-2-pentenal and, 4-phenyl-2-pentenal and4-phenyl-3-pentenal may be carried out l by means of reaction of aphenyl lower alkanal (e.g. hydrotropaldehyde,

where it is desired to produce 4-phenyl-2-pentenal;phenyl-npropionaldehyde,

ZMR

where it is desired to produce S-phenyI-Z-pentenal) with a lithium saltof a Schiff base of acetaldehyde produced according to the conditionsset forth above (e.g. a Schiff base of acetaldehyde withcyclohexylamine) thereby forming a phenyl hydroxyl-substituted pentanalSchiff base. This hydroxyl-substituted pentanal Schiff base is thentreated with acid thereby forming a phenyl pentenal or a mixture of twophenyl pentenals (since in certain cases, e.g. when producing 4-phenyl-Z-pentenal and 4-phenyl-3-pentenal but not when producingS-phenyl-Z-pentenal, when the hydroxyl derivative is dehydrated toisomers with the double bond in two adjacent positions will be formed).(2) If desired, these isomers (when such isomeric mixtures are formed)may be separated by standard separation techniques, e.g. distillation orGLC techniques. (3) The pure isomers or mixtures thereof may, ifdesired, then be reacted with a suitable orthoformate and in addition alower alcohol or a mixture of different lower alcohols or a loweralkylene glycol or a mixture of lower alkylenc glycols or a mixture oflower alcohols and lower alkylene glycols in the presence of an acidicreaction promoter, such as paratoluene sulfonic acid, hydrochloric acidor a source therefor, such as acetyl chloride one or a mixture of thelower alkyl acetals and/or alkylene glycol acetals useful in ourinvention. The reaction sequence is generally illustrated as follows:

[(ngm ca and/or (R O) CH] +[RgOH and/or R OH or R R (OH)2] Acid Catalystwherein R is hydrogen or methyl; n is zero when R,,

is methyl; n is l when-R, is hydrogen;.wherein p is l or 2; one of thewavy or dashed lines represents a double bond and the other of the wavyor dashed lines represents a single bond; wherein when R is hydrogen thedashed line is a single bond only; wherein whe n t h e dashed line is adouble bond p is l and when the wavy line is a double bond p is 2; andwherein R and ,R' taken separately are the same ordifferent lowergalkyl,

-e. g. methyl, ethyl, propyl, i-propyl, n-butyl, t-butyhor i-butyl and Rand R,, taken together form a lower alkylene group; e.g. 1,2-ethylene;l,3-propylene; 1,3 butylene; l,4-butylene and 1,2-propylene. Aspecificillustration of this reaction sequence is as follows:

' aqueous-oxalic, QCldgSOlUtiOn.

12 steam distilling}the-reactionproducts from the said In the foregoingreaction sequence the initial reaction between the phenyl lower alkanaland the lithium salt of the Schiff base of acetaldehyde is bestperformed in the presence of a nonreactive solvent, such as benzene orether at temperatures of the order of 70C up to +20Cr It is best to mixthe reactants at 70C and allow the reaction mass to slowly warm to roomtem- 1 perature. Furthermore, it is most preferable that the reactantsbe in equimolar proportion. The concentration of reactants in thesolvents can vary from 0.5 molar up to 3 molar. The subsequentacidification which also gives rise to an in situ dehydration is mostpreferably performed using an aqueous oxalic acid solution and tantconcentration in the solvent may vary from 0.1 molar up to 2 molar. (2)The S-phenyl-Z-pentenal may, if desired, then be reacted with a suitableorthoformate and in addition a lower alcohol or a mixture of differentlower alcohols or a lower alkylene glycol or a mixture of lower alkyleneglycols or a mixture of lower alcohols and lower alkylene glycols in thepresence of an acidic reaction promoter, such as paratoluene sulfonicacid, hydrochloric acid or 'a-source therefor such as acetyl chloride,thus forming one or a mixture of the lower alkyl acetals and/onalkyleneglycol acetals useful in our invention. The reaction sequence isillustrated as follows:

When the materials of this invention, the 4- and 5- phenyl pentenals andthe lower alkyl diacetals and lower alkylene acetals of 4-, andS-phenyl-pentenals are used as food flavor adjuvants thes nature of thecoingredients included with the 4- and S-phenylpentenals and lowerdialkyl acetals or lower alkylene acetals thereof in formulating theproduct composition will, (i.e., as a foodstuff per se oralternativelyas a flavoring composition adapted to beadded to a foodstuff at somesubsequent point of time) serve'to alter the organolepticcharacteristics of the ultimate foodstuff treated therewith.

Substances suitable for use herein as co-ingredie'nts or flavoringadjuvants are well known' in the art for such use being extensivelydescribed in therelevant 'literature. Apart from the requirement thatany'such material be ingestibly acceptable, and thus non-toxic orotherwise non-deleterious, nothing particularly critical resides in theselection thereof. Accordingly, such ma terials, which may in general becharacterized as flavoring adjuvants or vehicles comprise broadly,stabilizers,

thickeners, surface active agents, conditioners, flavor-,-

ants and flavor intensifiers.

Stabilizer compounds include preservatives, e.g., so-" Thickenercompounds include carriers, binders, protective colloids, suspendingagents, emulsifiersand the like,'e.g., agaragar; carrageenan;celluloseand cellulose derivatives such'as carboxymethyl cellulose ande.g., fatty acids such as capric acid, caprylic acid, palmitic acid,myristic acid and the like, monoand diglyceridesof fatty acids,lecithin, defoaming and flavordispersing agents such as sorbitanmonostearate, potassium stearate, hydrogenated tallow alcohol and thelike.

Conditioners include compounds such as bleaching and maturing'agents,e.g'i, benzoyl peroxide, calcium. peroxide, hydrogen peroxide and thelike; starch modifiers such'as 'p'eracetic acid, sodium chlorite, sodiumhypochlorite, propylene oxide, succinic anhydride and the like, buffersand neutralizing agents, e.g., sodium acetate, ammonium bicarbonate,ammonium phosphate, citric acid, lactic acid, vinegar and the like;colorants, e.g., carminic acid, cochineal, turmeric and curcuma and thelike; firming agents such as aluminum so- 7 dium sulfate, calciumchloride and calcium gluconate; te'xturizers; anti-caking agents, e.g.,aluminumcalcium sulfate and tribasic calcium phosphate; enzymes; yeastfoods, e.g., calcium lactate and calcium sulfate; nutrientsupplements,e.g., iron salts such as ferric phosphate, ferrous glucor-ate and thelike, riboflavin, vitamins, zinc sources such as zinc chloride, zincsulfate and the like.

Flavorants and flavor intensifiers include organic acids, e.g., fattysaturated acids, unsaturated acids and amino acids; alcohols, e.g.,primary and secondary alcohols; esters, carbonyl compounds includingaldehydes and ketones as well as lactones; cyclic organic materialsincluding benzene derivatives; isocyclics; heterocyclics such as furans,particularly pyridines, pyrazines (particularly monoalkyl, dialkyl,trialkyl and tetraalkyl substituted pyrazines) and the like,sulfurcontaining materials including thiazoles, disulfides, thiols,sulfides, aldehydes, (for example, 3-phenyl-4- pentenal,3-phenyl-3-pentenal, 3-phenyl-2-pentenal,

2-phenyl-2-pentenal, and 2-phenyl-3-methyl-2-butenal;

disulfides and the like; so-called flavor potentiators such asmonosodium glutamate, guanylates, inosinates, natural and syntheticflavorants such as vanillin, ethyl vanillin, diacetyl, phenethyl2-furoate, maltol, natural gums and the like; spices, herbs, essentialoils and extractives including bitterness principles such as theobromin,caffein, naringin and other suitable materials creating a bitter effect.

The specific flavoring adjuvant selected for use may be either solid orliquid, depending upon the desired physical form of the ultimateproduct, i.e., foodstuff, whether simulated or natural, and should, inany event, be capable of providing an environment in which the 4- or5-phenyl-pentenals or dilower alkyl acetals or lower alkylene acetalsthereof can be dispersed or admixed to provide a homogeneous medium. Inaddition, selection of one or more flavoring adjuvants as well as thequantities thereof will depend upon the precise organoleptic characterdesired in the finished product; thus, in the case of flavoringcompositions, ingredient selection will vary in accordance with thefoodstuff to which the flavor and aroma are to be imparted. lncontradistinction, in the preparation of solid products, e.g., simulatedfoodstuffs, ingredients capable of providing normally solid compositionsshould be selected such as various cellulose derivatives.

As will be appreciated by those skilled in the art, the 1 amount of 4-or S-phenyl-pentenal or di-lower alkyl acmerely deficient in naturalflavoror aroma. Thus, the

primary requirement is that the amount selected be effective, i.e.,sufficient to alter the organoleptic characteristics of the parentcomposition, whether foodstuff per se or flavoring composition.Thus,,the use of insufficient quantities of the 4- or S-phenyl-pentenalor dilower alkyl acetal or lower alkylene acetal thereof will, ofcourse, substantially vitiate any possibility of obtaining the desiredresults while excess quantities prove needlessly costly and in extremecases, may disrupt the flavor-aroma balance, thus provingself-defeating. Ac-

1.6 cordingly, the terminology effective amount and sufficient amount isto be accorded a significance in the context of the present inventionconsistent with the obtention of desired flavoring effects.

Thus, and with respect to ultimate food compositions, it, isfoiind thatquantities of 4- or S-phenylpentenal or di-lower alkyl acetal or loweralkylene acetal thereof ranging from a small but effective amount, e.g.,0.1 part per million up to about 20 parts per mil lion by weight basedon total composition are suitable. Concentrations in excess of themaximum quantities stated are not normally recommended since they failto provide commensurate enhancement of organoleptic properties. In thoseinstances wherein the 4- or 5- phenyl-pentenal or di-lower alkyl acetalor lower alkylene acetal thereof is added to the foodstuff as anintegral component of a flavoring composition, it is; of course,essential that the total quantity of flavoring composition employed besufficient to yield an effective 4- or 5-phenyl-pentenal(or di-loweralkyl acetal or lower alkylene acetal thereof) concentration in thefoodstuff product.

Food flavoring compositions prepared in accordance with the presentinvention preferably contain the 4- or 5-phenyl-pentenal or di-loweralkyl acetal or lower alkylene acetal thereof in concentrations rangingfrom about 0.4 up to 20% by weight, based on the total weight of saidflavoring composition.

The compositions described herein can be prepared according toconventional techniqueswell known in the art for such purposes. Thus,liquid products as typifled by cake batters eg'g nog and chocolate milkcan be formulated by merely admixing the involved ingredients within theproportions stated in a suitable blender to obtain the desiredconsistency, homogeneity of dispersion, etc. Alternatively, flavoringcompositions in the form of particulate solids can be convenientlyprepared by admixing the florS-phenyl-pentenal or dilower alkyl acetalor, lower alkyl e ne acetal thereof with, for example, gum aralSicSQgumtragacanth, carrageenan and the like, and ther aftenfspraydrying theresultant mixture whereby to jobtainthe particulate solid product.Pre-prepared nrnixes in powder form e.g., cocoa mix may be obtained bymixing the dried solid components e .g.','rr1ilk solids sugar and thelike and 4- and 5-phenylpen ten'al or di-lower alkyl acetal or loweralkylene-acetal thereof in a dry blender until the requisite degree ofuniformity is achieved.

It is presently preferred to combine with the 4- or 5- phenyl pentenalordi-lower alkyl acetal or lower alkylene acetal 'thereof the followingflavoring adjuvants: vanillin, heliotropine, amyl isovalerate, butylisovalerate, methyl 'cyclopentenolone, citral, amyl alcohol, ethyl,alcohohphenyl ethyl acetate, di-acetyl, isoamylalcohol furfural, phenylacetic acid, isovaleraldehyde, phenyl ethyl alcohol and maltol andmixtures thereof.

The compounds of our invention have been found to be useful in perfumerywhere twiggy, cuminic, citrus, green, cutgrass, linseed or cinnamonnotes are desired. The 4- or S-phnyl-pentenals or di-lower alkyl acetalsor lower alkylene acetals thereof of this invention and an auxiliaryperfume ingredient, including, for example, alcohols, aldehydes,nitriles, esters, cyclic ethers,

and natural essential oils, may be admixed so that the combined odors ofthe individual components produce a pleasant or desired fragrance. Suchperfume compositions usually contain (a) the main note or the bouquet orfoundation stone of the composition; (b) modifiers which round off andaccompany the main note; (c) fixatives which include odorous substanceswhich lend a particular note to the perfume throughout all stages ofevaporation and substances which retard evaporation; and (d) topnoteswhich are usually low boiling fresh smelling materials.

In perfume compositions the individual component will contribute itsparticualr olfactory characteristics, but the overall effect of theperfume composition will be the sum of the effects of each of theingredients. Thus, the individual compounds of this invention, ormixtures thereof, can be used to alter the aroma characteristics of aperfume composition, for example, by utilizing or moderating theolfactory reaction contributed by another ingredient in the composition.

The amount of the acetal compound of this invention which will beeffective in perfume compositions depends in many factors, including theother ingredients, their amounts and the effects which are desired. Ithas been found that perfume compositions containing as little as 1% ofthe compounds of this invention or even less, can be used to impart ascent odor to soaps, cosmetics, and the other products. The amountemployed can range up to 20% of the fragrance components and will dependon considerations of cost, nature of the end product, the effect desiredon the finished product and the particular fragrance sought.

The 4- and S-phenyI-pentenals or di-lower alkyl acetals and loweralkylene acetals thereof of this invention are useful in a perfumecomposition as an olfactory component in detergents and soaps; spaceodorants and deodorants; perfumes; Colognes; toilet waters; bathpreparations, such as bath oils and'bath solids; hair preparations, suchas lacquers, brilliantines, pomades and shampoo; cosmetic preparations,such as creams, deodoroants, hand lotions, and sun screens; powders,such as talcs, dusting powders, face powders and the like. When used asan olfactory component of a per-.

fumed article, as little as 100 ppm of one or more of the preferredacetals of this invention will suffice to impart either a green,balsamic, cinnamic-like character to the topnote of the fragranceemployed or a green, rosy character to the topnote of the fragranceemployed or a green, rosy note to the body of the fragrance em ployed.Generally, no more than 0.5% of the cornpounds of this invention basedon the ultimate end product is required in the perfume composition.

In addition, the perfume composition or fragrance composition of thisinvention can contain a vehicle or carrier for the acetals alone or withother ingredients. The vehicle can be a liquid such as an alcohol,nontoxic alcohol, non-toxic glycol, or the like. The carrier can also bean absorbent solid, such as a gum (e.g. gum arabic) or components forencapsulating the composition (such as gelatin).

It will thus be apparent that the acetals accordingto the presentinvention can be'utilized to alter the sensory property, particularlyorganolepticproperties, such as flavor and/or fragrance ofa wide varietyof consumable materials.

The following Examples are given to illustrate embodiments of theinvention as it is presently preferred to practice it. It will beunderstood that these Examples are illustrative, and the invention isnot to be considered as restricted thereto except as indicated in theappended claims.

EXAMPLE I PREPARATION OF 4-PI-IENYL-4-PENTENAL 3.50 grams ofdi(trimethylsilyl)amine is dissolved in IS ml diethyl ether and stirredat 0C as l2.5 ml of 1.6 N n-butyl lithium in hexane is added by syringeat 0C. 2.50 Grams of the Schiff base of acetaldehyde withcyclohexylamine is added. The resulting mixture is then cooled to C and4.0 grams of a-bromomethyl styrene is added. The reaction mass is thenallowed to warm to room temperature and is maintained at approximately10C for a period of 12 hours. [0 ml of water is then added to thereaction mass followed by approximately 4 ml of concentratedhydrochloric acid whereby. the pH of the reaction mass is l.

The resulting mixture was extracted with diethyl ether and the productwas isolated as follows: The ether solution was stirredwith an aqueoussolution containing 1.5 grams of Girards reagent P* and 1 ml aceticacid. After approximately one hour, the organic phase was separated fromthe aqueous phase and the aqueous phase is extracted twice with diethylether. The aqueous phase is then treated with 2 ml. concentratedhydrochloric acid and stirred with diethyl ether for approximately 4hours. The resulting mixture separates into two phases and the phasesare separated. The diethyl ether layer is washed with water andsaturated sodium bicarbonate and then dried over anhydrous sodiumsulfate and evaporated to give 0.5 gram of a light yellow oil which is98-99% pure (as determined by GLC). NMR, mass spectral and IR analysisyield the information that the resulting product is 4-phenyl-4-pentenal. The NMR analysis is as follows: Note carboxymethylpyridiniumChloride hydrazide.

ppm Interpretation 9.76 HC=O (s) IH 7.3l Aromatic protons 5H 5.08 AR C2H 5.30 II H H 2.68 =C-CH 4H -CH C=O EXAMPLE II PREPARATION OFS-PHENYL-Z-PENTENAL EXAMPLE Ill- PREEARATION OF 4-PHENYL-2-PENTENAL Aliso 4-PHENYL-3-PENTENAL,

grams of diisopropylamine in 2.5 ml .etherad mixed with 9.0 ml of 2.3Nphenyl lithium (in asol vent' containing 70 parts of benzene and 30parts of diethyl I hyde is added. After 'lS rni n grams of the ,imineoff cyclo cooled usinga dry icebath' to allowed to warm to room.ternperature and maintained at approximately 20C for a perio'd of '5hours. Water is then'added to the reaction rnass followed By, l sulfurica id in order that the of the, rea' :tiori mass is approximately -l,.The mixture, is then stirred: for approximately l5ininutesandtlieorganicse is sepa- 3 sodium rated and washed with water andtheii satubicarbonateJTheorganiclayer isgtlien evaporated and theresulting-residue is stirredwith 'Giraj'rd reagent P*-in "water with 1ml of aeetic acid. After approximately one-half-.-hour the resultingaqueous layer is ext' racted several timeswithdiethyi ether. The

ether) and the resulting mixturejs stirredat 0C for'a period of minutes.2.60 Grams of the 'c'yclohe'xy'li- Y mine of acetaldehyde is added at 0Cand the resulting.

mixture is stirred for a period of minutes." The mixture is then cooledusing a dry ice bath to T7OC and 2.68gms of hydrotropic aldehyde isadded theretqThe I mixture is then allowed to warm'gradually andkerptat; room temperature for a period of approximately 15 hours. Wateris added to the reaction mass at this point and the mixture is stirredfor a period of 15 minutes. The two resultingliquid phases are thenseparated and the organic phase is evaporated. The resulting organicresidue is then steam distilled from aqueous oxalic acid 15 grams in 150ml. water) yielding250 ml. distillate. The distillate is then extractedwith diethyl ether and the ether extract is washed using aqueous sodiumbicarbonatc, and dried over anhydrous sodium sulfate and evaporatedyielding 2.10 grams of a yellow oil which is a mixture of4-phenyl-2-pentenal and 4-phenyl-3- pentenal. Each of the4-phenyl-2-pentenal and 4-phenyl-3-pentenal is separated using gasliquid chromatography and identified using IR, NMR and GLC techniques.The NMR spectrum of 4-phenyl-2-pentenal is of diisopropyl amine isdissolved in 20 ml 1.20 grams ml of 2.3N phenyl diethyl ether andstirred at 0C as 4.4

etherextract is'dis'carded' anditheaqueous layer is tlien treated with'3mlofc'oncentratedhydrochloric acid and theriextra'ctedwith'diethyLe-ther.The-diethyl ether layer: is then washed with 1water,.saturated sodium bi- I carbonate solution, dried over anhydrous sodiumsul fate and evaporated to yield 0.64, grams of a yellow oil having apurity of 99.5%. lR,- NMR andmass. spectral analysis yield informationthat the product is 5-phenyl-. 4-pentenal'. The NMKan'alysisof5.-.phenyl-,4-pentenal is as follows:

Note *1 carhoxymethylpyridinium chloride hydrazide.

; i Naircisse' Fragrance Fonnulation t 1 n l s L'The' following mixtureis prepare lcohoi" g cortex lemony n'bt therebyjmproving 'al j ovenarcisse for- 'ulati'OnL-[The -phenyhl penterral imparts a green,

2 sty'rallyl. diirriinicmote to the ,narcisse formulation.

1 E A PL v1 New Mown Hay Perfume Formulation The following formulationis prepared:

Ingredients Parts Honey base 25 Lavandin 60 Hawthorne 20 Acetanisol 5n-Butyl quinoline 3 Anisic aldehyde l5 Chamomile l Mate absolute 50% 5Coumarin l S-PhenyI-Z-pentenal 10 S-Phenyl-4-pentenal 5 TheS-phenyl-Z-pentenal imparts to the above formulation a cutgrass,cinnamon note. The 5-phenyl-4- pentenal imparts to this formulation anatural, fatty, green undertone.

EXAMPLE Vll GRAPEFRUIT FLAVOR The following formulation is prepared:

lngredients Parts Grapefruit oil Bergamot oil Citral Amyl alcohol Eth '1acetate 5-P enyl-4-pentenal When the above grapefruit formulation isadded to water at the rate of 1%, an excellent grapefruit drink isprepared. The 5-phenyl- 4-pentenal gives a fruitier peeliness to theinstant formulation thereby rendering it more desirable. The effectrendered by the S-phenyl- 4-pentenal can also be rendered by using 0.5parts of 5-phenyl-2-pentenal.

EXAMPLE Vlll COCOA FLAVOR The following formulation is prepared:

ingredients Pans Dimethyl sulfide 0.2 Phenyl ethyl acetate 0.6 Diacctylin propylene glycol) 0.2 lsoamyl alcohol 0.1 Furfural (50% in propyleneglycol) 0.2 Phenyl acetic acid 12.0 4-Phenyl-4-pentenal 30.0lsovaleraldehyde 38.0 Phenyl ethyl alcohol 3.0 Benzaldehyde 1.0 Maltol20.0 Vanillin 60.0 Ethyl alcohol 834.7

The 4-phenyl-4-pentenal adds an intense cocoa-like note to thisotherwise bland chocolate flavor formulation. The 4-phenyl-4-pentenalcan be replaced by 60 parts of 4-phenyl-4-pentenal diethyl acetal andthe same effect will be imparted to the overall formulation but theshelf life of the formulation will be tripled.

EXAMPLE IX BASIC WALNUT FORMULATlON The following formulation isprepared:

The addition of 4-phenyl-4-pentenal at the rate of 5% to the basicformulation adds a note as found in fresh walnut kernels, improving thenatural character of this flavor. Both the flavor with the4-phenyl-4-pentcnal and without the 4-phenyl-4-pentenal were compared atthe rate of 10 ppm in water.

What is claimed is:

1. A Schiff base having the structure:

wherein X is a moiety selected from the group consisting of:

2. The Schiff base of claim 1 wherein X is a moiety having thestructure:

3. The Schiff base of claim 1 wherein X is a moiety having thestructure:

1. A SCHIFF BASE HAVING THE STRUCTURE:
 2. The Schiff base of claim 1wherein X is a moiety having the structure:
 3. The Schiff base of claim1 wherein X is a moiety having the structure: